Mission Type: Orbiter
Launch Vehicle: Soyuz-Fregat
Launch Site: Baikonur Cosmodrome, Kazakhstan
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 1240 kg in total, including 93 kg of payload and about 570 kg of propellants.
1) UV and IR Spectrometer for solar/stellar occultation and Nadir Observations (SPICAV/SOIR)
2) UV-visible-near-IR imaging spectrometer (VIRTIS)
3) Analyzer of Space Plasma and Energetic Atoms (ASPERA)
4) Venus Radio Science (VeRa)
5) Venus Monitoring Camera (VMC)
6) Magnetometer (MAG)
7) High Resolution Infrared Fourier Spectrometer (PFS)
Spacecraft Dimensions: 1.5 x 1.8 x 1.4 m (excluding solar wings). With the solar wings extended, Venus Express measures about 8 m across.
Spacecraft Power: Solar panels
European Space Agency Venus Express Fact Sheet, http://www.esa.int/esaSC/SEM08K2VQUD_0_spk.html
Venus Express is Europe's first mission to Earth's twin world. Venus is a place of many mysteries waiting to be solved. The big question is: why did a planet so similar to Earth in size, mass and composition evolve so differently over the course of the last 4 billion years?
The mission's major objective is the first global examination of the atmosphere of Venus. The very hot and dense atmosphere appears to be completely different from the one around Earth. Existing meteorological models fail to predict the behavior of Venus' thicker blanket of gases.
Venus Express' objectives include the study of:
- the huge greenhouse effect on Venus (the strongest found in the Solar System)
- the hurricane force winds that permanently encircle the planet
- the mysterious ultraviolet absorption features at an altitude of about 80 km
- the way solar wind particles interact with the upper atmosphere
- the surface and geological activity
- the similarities/differences with our own planet
Venus Express makes use of two instruments originally built as flight spares for Mars Express and Rosetta, as well as two new instruments. It carries seven scientific instruments:
UV and IR Spectrometer for solar/stellar occultation and Nadir Observations (SPICAV/SOIR)
SPICAV/SOIR is searching for the small quantities of water in the atmosphere. It is also looking for sulphur compounds and molecular oxygen, and it is determining the density and temperature of the atmosphere at 80-180 km altitude.
UV-visible-near-IR imaging spectrometer (VIRTIS)
VIRTIS is studying the composition of the lower atmosphere, below the cloud decks at 35-40 km altitude, and it is tracking the clouds at ultraviolet and infrared wavelengths. This is allowing scientists to study the atmospheric dynamics at different altitudes, and to build the first 3D view of the atmospheric structure.
Analyzer of Space Plasma and Energetic Atoms (ASPERA)
ASPERA is investigating the interaction between the solar wind and the atmosphere by measuring outflowing particles from the planet's atmosphere and the particles of the solar wind. It is studying how molecules and ions escape from the planet.
Venus Radio Science (VeRa)
VeRa uses the powerful radio link between the spacecraft and Earth to investigate the conditions in the ionosphere. Scientists are also using it to study the mass, density, temperature and pressure of the atmosphere from 35-40 km up to 100 km altitude, and to determine the roughness and electrical properties of the surface. VeRa is also allowing the conditions of the solar wind in the inner Solar System to be deduced.
Venus Monitoring Camera (VMC)
VMC is a wide-angle multi-channel camera able to image the planet at near-infrared, ultraviolet and visible wavelengths. It is providing global images of the planet, studying the cloud dynamics and imaging the surface. In addition, it is assisting in the identification of phenomena seen by other instruments. It is a new instrument.
Venus has no detectable internal magnetic field and the field around the planet is entirely due to the interaction between the solar wind and the atmosphere. MAG is studying this process and helping in understanding the effect this has on the atmosphere. It is a new instrument that reuses the sensor design from the Rosetta Lander.
Venus Express' High Resolution Infrared Fourier Spectrometer (PFS) has unfortunately never been operational, owing to a malfunction that could not be fixed by a series of attempts performed in space. The pointing mirror is stuck in its closed position, preventing the spectrometer (otherwise working perfectly) from seeing its targets. PFS was meant to measure the temperature of the atmosphere at altitudes of 55-100 km at a very high resolution, and to make composition measurements of the atmosphere. It was also meant to measure the surface temperature and thereby search for volcanic activity. Thanks to careful scientific planning and optimized use of the other instruments, several of the PFS's scientific objectives are being achieved.